Presently, surfaces of roads, driveways, pathways and patios are covered with a variety of materials shaped in the form of paving tiles or the like. Typically, such paving and paving tiles are made of compositions such as from cementitious materials which include blended sands, UV resistant natural oxides, optionally natural stones and dry cement to bind the composite material together. Alternatively the compositions could consist of clays mixed with some or all of the above materials, and fired to high temperatures to create the tiles or pavers. However these traditional materials have several shortcomings.
A key disadvantage of such concrete and fired clay materials is impermeability to fluids, in particular, water. Areas covered by paving tiles or pavers are typically arranged such that surface water is collected at a drainage point and directed to flow to storm water outlets and outfall waterways, carrying with it all manner of pollutants and contaminants collected from the impervious surface. Upon discharge, the pollutants contaminate those outfall waterways, rendering them unsuitable as urban water resource, and unable to sustain normal marine life.
Further, impervious pavements with stormwater collection systems prevent stormwater from returning to subterranean aquifers, which are the natural collection points for stormwater, resulting in a reduction in water levels of subterranean aquifers and increase in salinity of the subterranean water. This renders subterranean aquifers unsuitable as an urban water resource.
Additionally when insufficient water drainage occurs, eg. from rain water or cleaning water, water collects or pools on the surface. Such pooling often results in dangerous situations, including vehicular aquaplaning on tarmacs and roads as well as various personal injuries which occur from accidents on slippery surfaces, eg. public building entries, car parks and the like.
Further, traditional concrete based and fired, clay pavers exhibit brittle failure due to the nature of the elements in the compositions, and often break suddenly under higher weight loads as can occur with vehicular use.
The invention when used in the urban environment in place of similar impervious composite materials, filters pollutants from stormwater run off thus reducing pollution of outfall waterways, and allows storm water to return to traditional subterranean aquifers by flowing through the pavement, thereby reducing the depletion and salination of important urban water resources.